Remote sensing systems are used to acquire information about an object or target without making physical contact with the object. For example, optical sensing systems, such as Light Detecting and Ranging (LIDAR) systems, use reflected light to determine ranges to targets, as well as to perform imaging or mapping of the target terrain. LIDAR systems may be carried by an airborne platform (e.g., airplanes, satellites, etc.) to capture optical image data from overhead (e.g., nadir looking) views of a geographical area of interest. The raw image data captured using LIDAR, etc., may be processed into a desired format, such as a digital elevation model (DEM), for example.
Some LIDAR systems include an active illumination system which includes components to scan a laser (or other light source) beam over a target area. Such a configuration may be desirable in that increasing the speed of a scanner increases the area coverage rate of a sensor, thereby reducing operating costs. One example of a LIDAR system employing one or more rotating optical elements (e.g., mirrors, glass wedge (Risley) prisms or holographic optical elements (HOEs)) is the High Resolution Quantum LIDAR System (HRQLS) from Sigma Space Corporation of Lanham, Md. This system employs a pair of monolithic rotating glass Risley prisms. Another example is the Georgia Tech Research Institute (GTRI) bathometric LIDAR. This system employs a single rotating HOE with a fixed glass optical element for the transmit channel.
Despite the existence of such configurations, further enhancements for optical and laser imaging systems may be desirable in some applications.